Conventionally, there exist variety of disturbance factors against audio signal reproduction of various audio visual (AV) devices such as a television during audio output. Therefore, there has been proposed various techniques to obtain a true sound quality for the output sound.
For example, one of the conventional techniques automatically optimizes a frequency, amplitude, and a bandwidth of a digital audio filter, and equalizes a loudspeaker using the digital audio filter.
However, the conventional techniques do not focus on resonance in a housing to which the audio signal is output. Thus, the audio signal output by the conventional techniques contains a component corresponding to the resonance in the housing. As a result, a listener feels sense of discomfort from such audio signal.